(a) Field of the Invention
The present invention relates to a liquid crystal display.
(b) Description of the Related Art
Liquid crystal displays (LCDs) are among the most widely used types of flat panel displays. A typical LCD configuration includes a pair of panels provided with field-generating electrodes, and a liquid crystal (LC) layer interposed between the two panels. The LCD displays images by applying voltages to the field-generating electrodes, thus generating an electric field in the LC layer that orients the LC molecules within. These directionally-oriented molecules adjust the polarization of incident light.
One common LCD configuration utilizes a structure in which pairs of field generating electrodes are respectively formed on two opposing display panels. Among the two display panels, a plurality of pixel electrodes and thin film transistors are arranged in a matrix format on one display panel (hereinafter referred to as “thin film transistor array panel”), whereas color filters of (typically) red, green, and blue and a light blocking member are formed on the other display panel, and one common electrode covers the entire surface of this other display panel (hereinafter referred to as “common electrode panel”).
However, in this configuration, the pixel electrodes and the corresponding color filters are small, and disposed on opposite display panels, and are difficult to align properly. This LCD configuration is thus susceptible to alignment error.
To solve this problem, a color filter on array (COA) structure is sometimes employed. LCDs constructed in COA configurations have their pixel electrodes and color filters formed on the same display panel. More specifically, in this structure, a light blocking member as well as the color filter are formed on the same display panel as the pixel electrode.
After forming the color filter on the display panel, an organic layer having a predetermined thickness is formed to prevent components of the color filter from flowing into the pixel electrode or the liquid crystal layer. The pixel electrode and the light blocking member are then formed on the organic layer. Here, the upper surface of the light blocking member winds up being lower than the upper surfaces of various other layers, so that the top surface of the display panel is uneven. This results in a non-uniform cell gap, with step discontinuities generated at points where, for example, the light blocking members meet the pixel electrodes. Due to these step discontinuities in height, and thus in cell gap, the liquid crystal behaves differently at the edges of the pixel electrodes. This results in image defects such as stains or light leakage, effectively increasing average cell size.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.